Investment in Sunrise Energy (Condensed Balance Sheet - Sunrise) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets	$ 42,910	$ 39,361
Total assets	264,469	260,413
Total liabilities	75,478	77,079
Total liabilities and stockholders' equity	264,469	260,413
Sunrise Energy [Member]
Current assets	3,315
Oil and gas properties, net	6,837
Total assets	10,152
Total liabilities	854
Members' capital	9,298
Total liabilities and stockholders' equity	$ 10,152